实现新的计数器算法（将时间分片， 统计更加精准）

internal/utils/counters/span.go

@@ -0,0 +1,12 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package counters
+
+type Span struct {
+	Timestamp int64
+	Count     uint64
+}
+
+func NewSpan() *Span {
+	return &Span{}
+}